.tt{
    width: 80%;
    border-collapse: collapse;
    margin:20px auto;
}
.tt caption{
    font-weight: bold;
    letter-spacing:5px;
    font:25px/55px "微软雅黑";
}
.tt tr td,.tt tr th{
    border: 1px solid #d9d9d9;
    padding: 8px;
    text-align: center;
    font:14px/28px "微软雅黑";
}

.tt tr:hover{
    background-color: #f4ffcb;
}